In gaming devices such as slot machines there is incorporated a device commonly known as a coin acceptor which detects and signals the insertion into the device of the proper coin for activation of the gaming device. Usually such coin acceptors perform several functions. In the first instance, the acceptor must detect that a coin of the proper size and weight has been inserted. To be effective, the acceptor must also detect the passage of counterfeit coins commonly referred to as slugs. The slugs can be manufactured to the proper weight and size requirements but not have the silver content of a valid coin. After passing the above-identified tests, the coin usually is passed by a sensing mechanism which detects the passage of an accepted coin and activates the machine.
Such coin acceptors usually operate to reject any coin not meeting all the tests mentioned above. That is, the rejected coin is deflected and caused to pass through a different passage for return to the owner instead of passing through a good coin passage with the owner being credited for paying that amount.
Usually such an acceptor includes passages sized to accept coins no larger than a suitable coin, pivotable weight actuated levers which serve to deflect into a reject passage, coins of lesser weight than a suitable coin, and deflecting members which project each coin at an angle to the original path in a manner such that coins having characteristics other than a suitable coin will not pass through the accepted passageway. In addition magnetic means are usually employed to detect slugs not having the silver content of a suitable coin.
Thus the primary purpose of a coin acceptor is to conduct various tests on the coin inserted into the machine to detect whether a proper coin is being offered for activation of the device. The rejected coins are usually deflected into a reject passage and returned to the owner. Sometimes in the case of slugs or counterfeit coins, the coin is actually retained in the acceptor and not returned to the owner.
There now exist several types of gaming and dispensing machines which call for the insertion of a plurality of suitable coins. In such gaming devices, the player can either increase the odds of winning or the amount paid off with winning by inserting multiple coins of the same type. Naturally each of these coins are passed in serial order through a coin acceptor having the capability of conducting the various tests previously described with a counter noting the passage of each suitable coin. In the past, the counter has usually comprised a microswitch having a lever arm which is tripped by the passage of a coin through an accepted coin passage. Thus a player can insert any number of coins up to a maximum number prior to actually playing the machine. Also, a plurality of similar coins must be inserted into some dispensing machines in which the cost of an item is a multiple whole number of the value of one suitable coin.
With the advent of such multiple coin machines, there has arisen the method of cheating the coin acceptor commonly referred to as "stringing". Generally stringing comprises the procedure of fastening to a suitable coin a string or thread. The string is lighweight and has no noticeable effect on the passage of the coin through the coin acceptor. Naturally the coin acceptor will pass the coin through the accepted coin passage because the coin is suitable for acceptance and meets all the tests.
Subsequently the coin passes the counter which as stated before, has in the past, been a microswitch having a lever extending into the accepted coin passage. The lever will be tripped once by passage of the coin. In the normal operation of the coin acceptor, the passage of several coins in succession will activate the machine in the normal manner.
However with the stringing procedure, once the accepted coin has passed through the accepted coin passageway a sufficient distance to trip the microswitch, it is moved back past the switch trip mechanism by pulling on the string a very short distance and then allowed to pass once again past the trip lever. Thus the coin acceptor indicates the passage of several suitable coins past the trip lever when in fact only one suitable coin has been inserted and is being held in the coin acceptor. It is the primary purpose of this invention to provide a coin detector which prevents the cheating procedure known as stringing.